1. Field of the Invention
The present invention relates to a display device and more particularly to a technology effectively applied to a liquid crystal display device using a plurality of drive circuit components for driving.
2. Background Art
Heretofore, active matrix type liquid crystal display devices have been widely used for, for example, the display units of personal computers (PCs) or television sets. These liquid crystal display devices each include a liquid crystal display panel and a drive circuit driving the liquid crystal display panel. In the conventional liquid crystal display devices, the drive circuit is formed on an IC chip called a driver IC or the like. The IC chip is mounted on a liquid crystal display panel or a printed circuit board connected to a liquid crystal display panel.
Further, the active matrix type liquid crystal display devices have been widely utilized as, for example, the display devices (display modules) of portable electronic devices such as mobile-phone handsets or PDAs. Still further, the liquid crystal display devices have also been used as, for example, the display devices (display modules) of portable computers called notebook computers or the like.
The display devices used for portable computers are generally larger in size (larger screen) and higher in definition (higher resolution) than those used for portable electronic devices such as mobile-phone handsets. Further, it is desired for the display devices used for portable computers in recent years to increase the number of gray scales. Therefore, the liquid crystal display devices used for portable computers are desired to be much higher in definition and more excellent in display quality.
However, in the case where multiple gray scale display is performed with a high-definition liquid crystal display device, for example, there arises a problem that the circuit scale of a drive circuit component is increased. In the liquid crystal display devices used for portable computers, an area for mounting an IC chip having a drive circuit is limited because of, for example, a reduction in the size and thickness of the computers. Therefore, it is desirable to form a drive circuit on a single IC chip. However, in the case where the circuit scale is increased, setting the drive circuit in a single IC chip increases the size of the IC chip, for example. Therefore, it becomes increasingly difficult to mount the IC chip on a limited area.
Accordingly, a method is proposed in which, in the liquid crystal display devices used for portable computers, a plurality of IC chips (drive circuit) are mounted on one liquid crystal display panel, and drive circuits of the respective IC chips are made to cooperate with each other to drive one liquid crystal display panel, for example. As a method for making a plurality of drive circuits mounted on one liquid crystal display panel cooperate with each other, a method for controlling a drive circuit of each IC chip by using an instruction signal is introduced in JP-A-2003-107520, for example.